Sitophilus oryzae adult
Sitophilus oryzae egg
Rhyzopertha dominica
Bactrocera dorsalis larvae
Corcyra cephalonica
Tribolium castaneum
Weevil and Pesticide Facts
o A couple of rice weevil could reproduce and damage
the rice for 4-6% by weight within 6 months (Jaitip,
2010).
o Chemical pesticides could not be used in organic rice.
Stored rice is damaged by weevil infestation.
o While pesticides pose risks to fumigators, consumers,
and the environment, rice weevil eggs are notoriously
resilient and can even survive some pesticide
treatments (de Sousa, 2023).
o Using too much pesticide on rice too often can be
harmful to human health by increasing the risk of
cancer (Asiah, 2019).
What is RF heating?
What is RF heating?
• Radio frequency (RF) heating is a new type of processing technology that uses electromagnetic waves in the frequency
range of 1–300 MHz.
• RF heating, as a type of dielectric heating method, involves the generation of heat as a result of the interaction
between an electromagnetic field and polarized molecules in the crops, which are either bipolar or ionic.
• It also penetrates the products and generates heat uniformly and instantaneously in the paddy kernel without regard
to convective or conductive media
• The electromagnetic waves are not form
of heat but form of energy that incur heat
by their interaction with material. There
are two dominant mechanisms for this
energy conversion which are ionic
conduction and dipolar rotation.
• The dipolar rotation happens in
molecules which are dipolar in nature
such as water. The water molecules are
excited by the rapidly changing polarity of
the electric field
RF heating applications
the electric field
RF heating applications
The heat generated promotes evaporation of moisture from the paddy surface and
stimulates moisture migration from the inside to the outside. The most successful past
applications have often combined two or more technologies (RF-HA, etc.)
• Drying and treatment of paddy (cv. Pathum Thani 1) seed (Pakawattana, 2013)
• Industrial-scale drying of paddy using hot air and RF (Chitsuthipakorn, 2023)
• Accelerated aging rice (Hussain et al., 2021; Sumreerath, 2010; Vearasilp et al., 2011)
• Fungus (Aspergillus flavus) control in milled rice (Vearasilp et al., 2011)
• Insects control in milled rice (Vearasilp et al.,2015; Hou et al., 2019; Jiao et al., 2017; Liu & Wang, 2019)
• Insects control in paddy seed ((Thanapornpoonpong et al., 2019)
• Fungus (Aspergillus flavus) control in wheat and corn seed (Jiao et al., 2016)
